Question

The vertex of this parabola is at (-2,-3). When the y-value is -2, the x-value is -5. What is the coefficient of the squared term in the parabola's equation? 5 re (-2, -3)​

Answer 1

Answer:

The coefficient of the squared term of the equation is 1/9.

Step-by-step explanation:

We are given that the vertex of the parabola is at (-2, -3). We also know that when the y-value is -2, the x-value is -5. Using this information we want to find the cofficient of the squared term in the parabola's equation.

Since we are given the vertex, we can use the vertex form:

$\displaystyle y=a(x-h)^2+k$

Where a is the leading coefficient and (h, k) is the vertex.

Since the vertex is (-2, -3), h = -2 and k = -3:

$\displaystyle y=a(x-(-2))^2+(-3)$

Simplify:

$y=a(x+2)^2-3$

We are also given that y = -2 when x = -5. Substitute:

$(-2)=a(-5+2)^2-3$

Solve for a. Simplify:

$\displaystyle \begin{aligned} -2&=a(-3)^2-3\\ 1&=9a \\a&=\frac{1}{9}\end{aligned}$

Therefore, our full vertex equation is:

$\displaystyle y=\frac{1}{9}(x+2)^2-3$

We can expand:

$\displaystyle y=\frac{1}{9}(x^2+4x+4)-3$

Simplify:

$\displaystyle y=\frac{1}{9}x^2+\frac{4}{9}x-\frac{23}{9}$

The coefficient of the squared term of the equation is 1/9.